Just bumped into this article on fstoppers: “Learn How To Fix Color Banding Using Just One Simple Tool”
The video shows you how to use a solar curve to spot potential banding in images and how to use the spatter tool to eliminate it.
This video shows Photoshop CS6 being used to correct the banding. However, I think spatter is also featured in Photoshop Elements. I’ll have a look later and see.